Spacecraft radiator system and method using east west coupled radiators

ABSTRACT

A spacecraft, along with an improved spacecraft radiator system and spacecraft heat dissipation method are disclosed. The spacecraft comprises a body with north, south, east and west facing panels. The spacecraft radiator system comprises one or more heat pipes disposed on each of the east and west facing panels to provide east and west facing radiator panels, heat dissipating equipment selectively mounted on the heat pipes on the east and west facing panels, and one or more coupling heat pipes that thermally interconnect the heat pipes on the east and west facing radiator panels together. By coupling the east and west facing radiator panels together in this manner, they share the heat load. This increases the thermal dissipation capability of the east and west facing radiator panels and radiator system by approximately  50 %. This offers a ten-fold increase in the ability to transfer heat from the east to west sides of the spacecraft.

BACKGROUND

[0001] The present invention relates generally to spacecraft, and morespecifically, to a spacecraft radiator system having coupled east andwest facing thermal radiator panels and a spacecraft heat dissipationmethod.

[0002] The assignee of the present invention manufactures and deploysspacecraft into geosynchronous and low earth orbits. Such spacecraft useone or more radiator systems to dissipate heat generated by equipment onthe spacecraft. The radiator systems transfer thermal energy to radiatorpanels where it is radiated into space.

[0003] Heat pipes connecting north and south radiator panels haveheretofore been used. Such structures are disclosed in U.S. patentapplication Ser. No. 09/377,442, filed Aug. 19, 1999, entitled“Spacecraft Radiator System Using Crossing Heat Pipes”, assigned to theassignee of the present invention, U.S. Pat. No. 3,749,156 issued toFletcher et al. entitled “Thermal Control System for a SpacecraftModular Housing”. Radiator panels on the east and west facing panelsthat are radiatively coupled to the north and south panels are disclosedin U.S. Pat. No. 5,372,183 entitled “Thermal Control Arrangements for aGeosynchronous Spacecraft” issued to Strickberger.

[0004] U.S. Pat. No. 3,749,156 discloses coupling the north southradiator panels and not the east and west panels. Neither U.S. Pat. No.3,749,156 nor U.S. Pat. No. 5,372,183 disclose or suggest mountingequipment on the east and west panels because of the high incident solarflux. U.S. Pat. No. 5,372,183 discloses radiatively coupling the north,south, east and west panels, but does not mount equipment on the eastand west panels nor does he consider using heat pipes to couple the eastand west panels together. U.S. Pat. No. 5,372,183 discloses the use ofthe east and west panels to improve the heat rejection capability of themain north and south payload radiator panels. In contrast, the presentinvention uses the east and west panels as payload radiators.

[0005] Accordingly, it is an objective of the present invention toprovide for heat dissipating apparatus comprising a spacecraft radiatorsystem having east-west coupled thermal radiator panels and a spacecraftheat dissipation method.

SUMMARY OF THE INVENTION

[0006] To accomplish the above and other objectives, the presentinvention provides for a spacecraft radiator system comprising coupledeast and west facing thermal radiator panels. A spacecraft is providedthat has radiator panels disposed on east and west facing sides thereof.Each east and west facing radiator panel comprises a set of heat pipes.Heat dissipating equipment is mounted on the east and west panel heatpipes. Another set of heat pipes, which are preferably loop heat pipes,are used to thermally couple the heat pipes of the east and west facingradiator panels.

[0007] Typically, east and west facing panels of the spacecraft offerlimited thermal dissipation capability due to the high incident solarload on those surfaces. In accordance with the present invention, theeast and west facing panels may be used to mount and dissipate thethermal load caused by equipment such as RF loads, feeds, switches,circulators and multiplexers (OMUXs), which can withstand temperatureshigher than normal payload electronics equipment.

[0008] In order to reduce the impact of the incident solar load, theeast and west panels are thermally coupled together and thereby, sharethe thermal load. By coupling the east and west panels together, thethermal dissipation capability of the east and west radiator panels ofthe radiator system can be increased by approximately 50%. In addition,the radiator system can accommodate an imbalance in payload thermaldissipation between east and west panels, thereby reducing requiredheater power.

[0009] A spacecraft heat dissipation method is also provided by thepresent invention. The spacecraft heat dissipation method comprises thefollowing steps.

[0010] A spacecraft is configured to have a body with north, south, eastand west facing panels. One or more heat pipes are disposed on each ofthe east and west facing panels. Heat dissipating equipment isselectively mounted on the heat pipes on the east and west facing panel.One or more coupling heat pipes thermally interconnect the heat pipes onthe east and west facing radiator panels together. The spacecraft islaunched into orbit. In orbit, heat coupled to the one or more heatpipes on the east and west facing panels by the heat dissipatingequipment is coupled to the one or more heat pipes of the other of theeast and west facing panels.

[0011] The present invention offers significant performance advantagesover U.S. Pat. No. 5,372,183, which merely radiatively couples thenorth, south, east and west sides of the spacecraft. The presentinvention utilizes heat piped radiator panels on both the east and westfacing panels and loop heat pipes to thermally couple the panelstogether. This offers a ten-fold increase in the ability to transferheat from the east to west sides of the spacecraft.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The various features and advantages of the present invention maybe more readily understood with reference to the following detaileddescription taken in conjunction with the accompanying drawing, whereinlike reference numerals designate like structural elements, and inwhich:

[0013]FIG. 1 illustrates a spacecraft employing an exemplary spacecraftradiator system in accordance with the principles of the presentinvention;

[0014]FIG. 2 is a flow diagram that illustrates an exemplary spacecraftheat dissipation method 30 in accordance with the principles of thepresent invention.

DETAILED DESCRIPTION

[0015] Referring to the drawing figures, FIG. 1 illustrates a spacecraft10 employing an exemplary spacecraft radiator system 20 in accordancewith the principles of the present invention. The spacecraft 10illustrated in FIG. 1 comprises a body 11 having north, south, east andwest facing panels 12, 13, 14, 15. The exemplary spacecraft 10 hasplurality of antennas 16 coupled to the east and west facing sides ofthe body 11.

[0016] In a typical spacecraft 10 the north and south facing panels 12,13 are used as radiator panels of the radiator system 20. In accordancewith the of the present invention in the present spacecraft 10 also usesthe east and west facing panels 14, 15 as additional radiator panels ofthe radiator system 20.

[0017] The east and west facing panels 14, 15 each comprise one or moreheat pipes 21. Heat dissipating equipment 22 or payload equipment 22 ismounted on the east and west panel heat pipes 21. Another set of one ormore coupling heat pipes 23, which are preferably loop heat pipes 23,are used to thermally couple the heat pipes 21 of the east and westfacing radiator panels 14, 15 together. The east and west panels 14, 15thus act in tandem to dissipate heat generated by the heat dissipatingequipment 22 or payload equipment 22 mounted on the east and west panelheat pipes 21.

[0018] Each of the loop heat pipes 23 comprise thin walled tubing thatmay be coupled between an evaporator and a condenser. The evaporator andcondenser are thermally coupled to the heat pipes 21 of the east andwest facing radiator panels 14, 15.

[0019] By coupling the east and west facing panels 14, 15 together inthis manner, the east and west facing panels 14, 15 share the heat load.This increases the thermal dissipation capability of the east and westfacing radiator panels 14, 15 and radiator system 20 by approximately50%. This offers a ten-fold increase in the ability to transfer heatfrom the east to west sides of the spacecraft 10. In addition, becausethe east and west panels 14, 15 are coupled together, the radiatorsystem 20 can accommodate an imbalance in payload thermal dissipationbetween the east and west panels 14, 15, thereby reducing requiredheater power.

[0020]FIG. 2 is a flow diagram that illustrates an exemplary spacecraftheat dissipation method 30 in accordance with the principles of thepresent invention. The exemplary spacecraft heat dissipation method 30comprises the following steps.

[0021] A spacecraft 10 is configured 31 to have a body 11 with north,south, east and west facing panels 12, 13, 14, 15, one or more heatpipes 21 disposed on each of the east and west facing panels 14, 15,heat dissipating equipment 22 selectively mounted on the heat pipes 21on the east and west facing panels 14, 15, and one or more coupling heatpipes 23 that thermally interconnect the heat pipes 21 on the east andwest facing radiator panels 14, 15 together. The spacecraft 10 islaunched 32 into orbit. In orbit, heat coupled to the one or more heatpipes 21 on the east and west facing panels 14, 15 by the heatdissipating equipment 22 is coupled 33 to the one or more heat pipes 21of the other of the east and west facing panels 14, 15.

[0022] Thus, a spacecraft radiator system comprising east and westfacing radiator panels and spacecraft heat dissipation method have beendisclosed. It is to be understood that the above-described embodimentsare merely illustrative of some of the many specific embodiments thatrepresent applications of the principles of the present invention.Clearly, numerous and other arrangements can be readily devised by thoseskilled in the art without departing from the scope of the invention.

What is claimed is:
 1. A spacecraft radiator system for use on a spacecraft having a body and north, south, east and west facing panels, the system comprising: one or more heat pipes disposed on each of the east and west facing panels; heat dissipating equipment selectively mounted on the heat pipes on the east and west facing panels; and one or more coupling heat pipes that thermally interconnect the heat pipes on the east and west facing radiator panels together.
 2. The spacecraft radiator system recited in claim 1 wherein the one or more coupling heat pipes comprise loop heat pipes.
 3. A spacecraft comprising: a body comprising north, south, east and west facing panels; and a spacecraft radiator system comprising: one or more heat pipes disposed on each of the east and west facing panels; heat dissipating equipment selectively mounted on the heat pipes on the east and west facing panels; and one or more coupling heat pipes that thermally interconnect the heat pipes on the east and west facing radiator panels together.
 4. The spacecraft recited in claim 3 wherein the one or more coupling heat pipes comprise loop heat pipes.
 5. A spacecraft heat dissipation method comprising the steps of: configuring a spacecraft 10 to have a body with north, south, east and west facing panels, one or more heat pipes disposed on each of the east and west facing panels, heat dissipating equipment selectively mounted on the heat pipes on the east and west facing panels, and one or more coupling heat pipes that thermally interconnect the heat pipes on the east and west facing radiator panels together; launching the spacecraft into orbit; and when in orbit, heat coupled to the one or more heat pipes on the east and west facing panels by the heat dissipating equipment is coupled to the one or more heat pipes of the other of the east and west facing panels.
 6. The method recited in claim 5 wherein the one or more coupling heat pipes comprise loop heat pipes. 